Scottish smoker left university and married (3)
I believe the answer is:
lum
'scottish smoker' is the definition.
(Scottish word for a chimney)
'left university and married' is the wordplay.
'left' becomes 'l' (common abbreviation).
'university' becomes 'u'.
'and' is a charade indicator (letters next to each other).
'married' becomes 'm'.
'l'+'u'+'m'='LUM'
(Other definitions for lum that I've seen before include "Scot. chimney" , "Scottish smoker" , "Chimney, in Scotland" , "(Scots) chimney" , "Scottish chimney" .)